Railway-traffic-controlling apparatus



Au 9 1927. Q

g F. w. LEE ET AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Oct. 27. 1926 I fi INVENTORSZ F 1 Leg and ',4 ,0, armada/1i,

Patented Aug. i 9,1927,

u NIT-ED isT FREDE IGK W. LEE, or BALTIMORE, MARYLAivD, ANDJLARS 0. one

res :Pareur o r1fcE..;-;

BURGH,PENNSYL ANIA,nssloirons TO THE UNION swrron & SIGNAL COMPANY, or swrssvnnn,v PENNSYLVANIA, A CORPORATION or-PnNNsYLvANIA;

RAI WAY-TRAFFIC-CONTROLLING' APPARATUS.

Application filed 0ctoher 27, 1926. Serial No;,144, 4s2.

Our invention relates to railway traffic controlling apparatus, and particularly to apparatus of the ,type wherein alternating currentis periodicallysupplied to' the track rails for the control of traffic governing mechanismwhich is responsivetosuch periodic supply of; alternating current but not tothe continuous supply of such current.

One lforl n of apparatus ofthe'character referred toisdisclosed andclaimed in application, for Letters Patent of the :United 'States filed by (1- S. Snavely on May. 29,

' 1926,.Serial-No. 112,491; .In the apparatus disclosedin that application, when a sectionis occupied bya trainand the next section in advance is unoccupied, alternating currents of two different frequencies are alter; nately applied to the track rails, and the train-carried apparatus is tuned to respond to one of these currents butnot the other. This tuning is usually accomplished by an electric filter, but we have found that under some conditions the filter may" respond to what we term fshock excitation, that is, V

end of section C -D and is'responsiveto the -60 cyclefcurrent supplied to these railsj by when an alternating current ,is'suddenly ap,-'

- filter receives animpulse whichcauses it to oscillate at its particular frequenciesand so tofalsely apply voltage to the train-carried apparatus, ,and'this may be true even though the current which is abruptly appliedis the current to whichthe filter is not tuned;

One feature of our invention is the provision ofmeans for preventing sudden ap-'- plication of current to the trackrrails, that is, means for delaying the increase of the current to its full value when the current is applied. V v e "We will describeone form of apparatus embodying our invention, and will-then point, out the novel features thereof in claims.

The accompanying drawing is adiagrann matic view showing one'form of apparatu embodymgour invention. I v v Referring to the drawlng, vthe reference characters -1 and 1 designate thetrack rails of a railway along which traflic normally moves in the direction indicated by-the arrow. These rails are clividedinto track sections of whic'h only one section CD is shown in the drawing. Located at the exit end of section (1-D are twotransformers E and E the secondaries 11 and 9 of vtimes supplied with alternating signaling current from "the secondary 12 offatrans;

former Ti", the primary 13 of which is constantlyconnected with a source of alternatingcurrent which; is not shown in the'draw 'ing.--fSimila1ly, the primary 8 of transformer E is, at times supplied with alter natlng current fromthesecondary 14' of a transformer T 9 the primary 15 of which is constantly connected with a source of alternating, current not shown, in the drawing.

the current supplied to transformer T may be (iOQcycles per second, and the current sup-.-

The currentssupplied to the transformers i T-.d ffer in frequency, andfas an example,

pliedtotransformer T may be 100 cycles f er second. I

The supply-ofcurrent to the transformers Eis controlled by'a relayGr, which I will term a coding relay, and this relay is in j turn controlled by a? trackrelayF whichisfl connected across the rails at the entrance transformer E. The codingrelay is terminal B of a; suitable source'of current,

through back contact of track relay F, winding of relay G, and back contact 4 of u relayG co-terminal O'o' f the same source of current. It Will be seen, therefore, that when section 0-D is unoccupied and track relay F is energized, relay G' will be at rest in its de-energized conditioiubut that when track relay F is 'de energizedthe coding re layG will be alternately energized and de energized, due to the fact that itsback con- 'tact f is included in the circuit for its winding, Y

The reference character H ydesignatesa reactor having a winding Tinclucledin the i primary circuit for transformer. E: This reactor also has a "winding 6 which is at times energized by a battery 16 tl1rough back contact 5 of coding relay G. The reference character H designates a similar reactor having a winding v7 included in'the primary circuit for transformer E 9, and a winding 6 which is atltimes energized-from battery 16 through frontcontact 5 of relay Gr. Each of these reactors H is so designed that when its windingt is de-energized the reactance of winding 7 winding 6 is energized from battery 16, the corejof the reactor is saturated so that winding 7 offers Substantially no reactance to the flow of. current to the associated transformer E. A. resistance 17 is connected across winding (3 of reactor H and a similar resistance 18 is connected across. winding 6 of reactor H I WVhen section CD is unoccupied and the back contact of relay G is closed, winding 6 of reactor H is energized so that winding winding 6 of reactor H dies down gradual 5 7 of-this reactor offers little reactance to the flow of current from transformer T and,

consequently, 6 0 cycle current is constantly supplied to the rails ofthe section and track relay F is energized. The circuit for w'indinc 6 of reactor H is then oaened so that substantially no'lOO cycle current is supplied to the track rails. When a train enters section CD, it opens relay F thereby starting the operation of coding relay G, so that the windings 6 of reactors H and H are alternatel 1 ener 'ized. The result of this isthe 'alternatesupply of cycle and 100 cycle current to'tlie rails of section C D. Each time that a winding 6 becomes energized, however, a brief interval elapses be fore the reactance of the associated winding 7 is reduced to its final value, and so a brief interval elapses before the corresponding alternating current builds up to its final value inthe track rails. 'Each' time that the back point of contact 5 opens, the current in claims without departing from the spirit and scope of our invent-ion.

Having thus described our what we claim is:

1. In combination with the track rails of a railway, a source of alternating current connected with said rails through a reactor, and means for periodically varying the effect of said'reactor.

2. In combination with the t-rack rails of a. railway, a source of alternating current invention,

connected with saidrails through a reactor,

is so high that sub-- stantially no current is furnished to the associated,transformer E, whereas when second winding. V y 4;. In combination withtlie' rails of a,ra1l''- a periodically operating contact,and'ineans controlled by said contact for periodically varying the effect of said reactor. I

3. In combination with the rails'of a Fall:

waytrack, a source of alternating current connected therewith, a reactor having a first winding interposed between said source and said rails, a second winding on said reactor effective when energized to substantially neutralize the reactance. of the first Winding, and means for periodically energizing said way'track, a source of alternating current connected therewith, a reactor having a first winding interposed between said source and said rails, a-second windingonsaid reactor effective when energized to substantially neutralize thereactance of the-first winding, means for periodicalyenergizing said sec- 0nd winding,and a resistance connected across said second winding to cause" the current in such winding to die down gradually when the winding becomes de-energize'd.

5. In combination withitlietrack rails'of a railway,- a source of alternating currenti connected therewith through a reactor, and

means for periodically saturating, the core of said reactor. r

(5. In combination with the'track rails of a railway, a source of alternating current of one frequency connectedtherewith through".

a reactor, a second source of 'a lternating current of a diiferentfrequency connected with said rails through a second reactoryand means for alternately neutralizing theeifect of said reactors;

7. In combination with the track rails of ZL I'ZLllWELY, a source of alternating current connected therewith, a reactor having a first winding interposed: between said source-and said rails, a second winding on said reactor effective when'energized tosaturate-the :core

of the reactor, and a circuit for said'second winding including a source of current and a periodically operated contact. f

8. In combination with the track rails of a railway, a source of alternating current connected therewith, a reactor h. ving'afirst winding interposed between said source and said r-ails,'a second winding on said'reactor effective when energized tosaturate the core of the reactor, a circuit for said second winding including a source of current and a periodically operated contact, and a resistance connected across said second winding to cause the current in such windingto die down gradually when said contact opens;

In testimony whereof we afiixour signatures.

riinnnnion w LEE.

LARS o. GRONDAHL. 

